Data collection image plate detectors

X-ray diffraction data were collected at room temperature on a MAR 300 mm image plate detector, using a Rigaku RU200 rotating anode operated at 50 kV and 100 mA (Table I). Data were processed with DENZO and scaled with SCALEPACK (8). Variations in the unit cell parameters for different crystals were less than 1.25 A, even between metal complexes and low temperature native structures. 

Area detectors combine the accuracy and wide dynamic range of scintillation counting the simultaneous measurement of many reflections, as with image plates and the advantage of direct collection data by computer, without a separate scanning step. One type of area detector is the multiwire or gas-proportional detector. As an example, the Mark I detector at the University of California, San Diego, as diagrammed in Fig. 4.19, consists of two perpendicular sets of parallel wires in a flat box filled with an inert gas. A window of beryllium permits entry of X rays from the front of the detector. 

Oscillation photography can be used in tandem with area detectors, but detector resolution limits the size of the unit cell from which data can be collected. Large unit cells, such as those of virus capsids, mean small reciprocal unit cells and large numbers of closely spaced reflections. Image plates are commonly used in such cases because of their greater spatial resolution. 

Sato, M., Yamamoto, M., Imada, K., Katsube, Y., Tanaka, N., and Higashi, T. A high-speed data-collection system for large-unit-cell crystals using an imaging plate tis a detector. J. Appl. Crysi. 25, 348-357 (1992). 

PEPC from E. coli was crystallized as described previously [1] with minor modifications. X-ray diffraction data were collected at station BL-6B of the Photon Factory, Japan. Intensity data were obtained using a Weisssenberg camera for macromolecule crystallography and imaging plates as a detector [5]. The data were processed using DENZO and scaled by the program SCALEPACK [6]. The crystal structure was determined by multiple isomorphous replacement method. 

Synchrotron radiation is used when a conventional, home, X-ray source with electronic or image plate area detector proves inadequate. This is not to belittle the X-ray tube or rotating anode. On the contrary, I have also endeavoured to develop conventional X-ray source data collection capabilities based on area detectors. It is fair to say that a synchro-... 

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